1. Field of the Invention
The present invention relates to an apparatus and method for launching a winged flying vehicle, especially, an apparatus and method suitable for horizontally launching a flying vehicle such as a spacecraft.
2. Description of the Related Art
Vertically launched rockets such as those used with the Space Shuttle are commonly known as flying vehicles used for space travel. However, vertically launched spacecraft are considered uneconomical in that fuel occupies a large portion of the spacecraft lift-off weight and furthermore, it is difficult to reuse the fuselage.
Therefore, spacecraft that take off and land horizontally like a common aircraft have recently been attracting attention since such spacecraft are thought to be more economical than the current rocket version. This is due to the fact that the fuel load can be reduced and the fuselage easily reused. Different types of horizontal launching methods for spacecraft have been proposed in order to make spacecraft more economical by further reducing the fuel load.
The following methods and apparatuses for horizontal launching have been proposed:
(1) One proposal involves an accelerating apparatus comprising a carriage for carrying a spacecraft, wherein the carriage is guided along a track. The carriage has a jet engine, and thrust is generated by irradiating a propellant with a laser ray. There is a laser ray-introducing portion that receives a laser ray from the forward direction, and the track has laser-irradiating equipment provided halfway at the track and the laser-irradiating equipment irradiates the laser ray-introducing portion (see Japanese Patent Publication No. 2861569, referred to as ‘the first related art’ hereinafter).
(2) Another proposal involves a glider-type space-launched aircraft that is towed by an aircraft (International Patent Publication WO96/15941, referred to as ‘the second related art’ hereinafter).
In the accelerating apparatus described in the first related art, the carriage is accelerated by a certain accelerating device, however, it is difficult to smoothly accelerate the spacecraft unless the direction of acceleration of the carriage is exactly identical to the direction of thrust of the rocket engine of the spacecraft. Furthermore, there is also the risk of carriage derailment. Additionally, there is the possibility of the carriage and the jet engine being damaged when the rocket engine of the spacecraft is started at the same time as the start of acceleration. Notwithstanding this fact, there is no description in the related art regarding appropriate timing for starting the rocket engine in order to prevent damage of the carriage and the jet engine. In this regard, high-temperature exhaust gas discharged from the jet engine can also damage the track or other structures.
With a spacecraft that is towed by an aircraft to climb to a specific altitude, such as the glider-type space-launched aircraft described in the second related art, it is extremely difficult to retrieve the spacecraft. This is especially the case when combustion proceeds abnormally in the rocket engine of the spacecraft after release from the towing aircraft, and it is difficult to safely land the spacecraft at an airfield. Additionally, the aircraft has to be large in order to be able to tow the spacecraft, making a long runway necessary in order for both the aircraft and the spacecraft to takeoff.